DON’T FORSAKE MOON FOR MARS SPACEFLIGHT 51; 153 : 2009
(Harrison H. Schmitt stands by the American flag during a moonwalk
on the Apollo 17 mission during the final journey to the moon in December 1972.)
In an article published in SPACE NEWS (Nov.24, 2008) Harrison Schmitt (Apollo 17) is absolutely right in objecting to the Planetary Society’s urging U.S. president –elect Barack Obama and Congress to achieve an earlier human Mars landing, thereby postponing a planned return to the moon first. There are several arguments from a medical standpoint why Schmitt’s objections are valid:
First, we must determine whether an astronaut can tolerate an extended presence of at least 20 months in a microgravity environment – the shortest predicted duration of a Mars mission. During the 438 day mission of a single Russian on Mir there was evidence of a potential serious insult to the lining of the blood vessels ( endothelium) with potential injury/ dysfunction, stemming from reductions of a clot buster and vessel dilator ( cGMP a second messenger of nitric oxide ). (1) This in turn can injure not only the vessels of the heart but any of the blood vessels of other organs as well.
Second ,we must determine whether exposure to inhalation of ultra -fine dust particles (< 100nm. ) in the habitats on the surface and enroute back to earth are tolerable since Irwin (Apollo 15 ) returned with extraordinary stress test blood pressure levels, probably on the day after return to over 275/125 mm. Hg. with a heart rate of only 132 / minute after just 3 minutes on a bicycle stress test ; this almost certainly was a complication of inhalation of dust since there is no hypertension with exposure to microgravity ( alone ) (2,3). To my knowledge – at this time – ultra fine dust (< 100 nm.) can NOT be removed with current devices. To develop the technology of removal of ultra-fine particles may require considerable time.
Third, since at least 1/3 of the adult population has hypertension and in case ultra -fine dust cannot be removed, we must determine whether a screening test to predict eventual hypertension in those astronaut candidates with normal blood pressure ( <130/80) is reliable with current tests .(4)
Fourth, although radiation levels on the Apollo missions were felt to be tolerable (5) we have no way of being absolutely sure whether this would be so on a Mars mission. Astronauts may therefore require gene therapy to offset the adverse effects of radiation which may require decades of research!
Fifth, I have stressed in several publications ( www.femsinspace.com ) that pharmaceuticals can not be utilized with space missions because of invariable malabsorption necessitating parenteral therapy by the use of a subcutaneous implanted multi-reservoir microchip device. There are also the problems with deterioration of some pharmaceuticals – no longer meeting U.S.P. standards- possibly related to radiation, and potential impairment in their metabolism and excretion because of eventual hepatic and renal dysfunction. Astronauts may therefore need gene therapy to offset this problem for a Mars mission.
Finally, since females have significantly greater protection from potential space flight- cardiovascular complications (6, 7) gender comparison studies on the moon will be required before undertaking a Mars mission or limit consideration of a Mars venture to females.
Since the seals were broken on all of the 840 pounds of rocks brought back after the Apollo missions various studies to determine – by non-invasive means –the potential injuries to the lining of the blood vessels by inhalation of dust, for example, will have to wait until return to the Moon, possibly not until the end of the next decade. (8)
Let’s be sure we’ve addressed at least these few issues before thinking of heading straight for Mars.
William J. Rowe FBIS
1. A Roessler, V Noskov, Z Laszlo et.al. Permanent depression of plasma cGMP during long term space flight. Physiol Res 50; pp 83-90, 2001.
2. WJ Rowe, Moon dust may simulate vascular hazards of urban pollution. J, Brit. Interp. Soc. ; 60 PP 133-36, 2007.
3. WJ Rowe, Moon dust and severe hypertension. Spaceflight 49; p 276, 2007.
4. W J Rowe, Astronaut screening. Spaceflight 49; P.477, 2007.
5. CA Berry, Medical legacy of Apollo. Aerospace Med 45; pp.1046-57, 1974.
6. W J Rowe, The case for an all-female crew to Mars. J. of Men’s Health and Gender 1 ; pp.341-344, 2004.
7. W J Rowe, Evolution and intelligent design. Spaceflight 48; p156, 2006.
8. J W Shields, LA Taylor, Petrologic constraints on the origin of the moon. In: Origin of the moon. Proceedings of the conference, Kona Hi. Oct 13-16, 1984. PP 173-203.